get_by_jsonpath匹配规则，未做空处理，需要优化下

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在./aomaker/cache.py155行，get_by_jsonpath方法需要增加expr_index为None时，返回list数字
获取响应结果中list参数时，会引发异常
jsonpath表达式：$..id
响应结果：
{ "code": 0, "msg": "操作成功", "data": [ { "create_user": 6, "body": null, "update_user": 6, "body_type": 0, "name": "用例163625", "directory_id": 332, "id": 281, "request_type": 1, "tag": null, "created_at": "2023-12-04 16:36:25", "url": "https://www.baidu.com", "status": 3, "updated_at": "2023-12-04 16:36:25", "request_method": "GET", "priority": "P0", "deleted_at": 0, "request_headers": "{}", "case_type": 0, "base_path": null }, { "create_user": 6, "body": null, "update_user": 6, "body_type": 0, "name": "用例164214", "directory_id": 332, "id": 282, "request_type": 1, "tag": null, "created_at": "2023-12-04 16:42:14", "url": "https://www.baidu.com", "status": 3, "updated_at": "2023-12-04 16:42:14", "request_method": "GET", "priority": "P0", "deleted_at": 0, "request_headers": "{}", "case_type": 0, "base_path": null } ] }

问题错误截图：